diff --git a/Makefile b/Makefile
index c1491d875..b2ed08a7d 100644
--- a/Makefile
+++ b/Makefile
@@ -158,13 +158,13 @@ pre-pr-validate: validate-content check-fact-ids
 	@echo "--- Content validation: PASS ---"
 
 pre-pr-fixtures:
-	@echo "Checking fixture staleness..."
+	@echo "Checking Rust->GDScript fixture staleness..."
 	@cd server && cargo test --test gen_fixtures -- --ignored
 	@if git diff --quiet client/tests/fixtures/; then \
-		echo "--- Fixtures: UP TO DATE ---"; \
+		echo "--- Rust fixtures: UP TO DATE ---"; \
 	else \
 		echo ""; \
-		echo "--- FIXTURES STALE ---"; \
+		echo "--- RUST FIXTURES STALE ---"; \
 		echo "  Protocol changed but fixtures not regenerated."; \
 		echo "  Stale fixtures make all client tests FALSE POSITIVES."; \
 		echo ""; \
@@ -174,6 +174,22 @@ pre-pr-fixtures:
 		echo "  Fix: commit the updated fixtures with your protocol change."; \
 		exit 1; \
 	fi
+	@echo "Checking GDScript->Rust fixture staleness..."
+	@$(MAKE) fixtures-client
+	@if git diff --quiet server/tests/fixtures/gdscript/; then \
+		echo "--- GDScript fixtures: UP TO DATE ---"; \
+	else \
+		echo ""; \
+		echo "--- GDSCRIPT FIXTURES STALE ---"; \
+		echo "  Protocol changed but GDScript fixtures not regenerated."; \
+		echo "  Stale fixtures make cross-encoder tests FALSE POSITIVES."; \
+		echo ""; \
+		echo "  Changed files:"; \
+		git diff --stat server/tests/fixtures/gdscript/; \
+		echo ""; \
+		echo "  Fix: commit the updated fixtures with your protocol change."; \
+		exit 1; \
+	fi
 
 # Branch-specific variants (faster, scope-appropriate)
 
diff --git a/client/tests/gen_client_fixtures.gd b/client/tests/gen_client_fixtures.gd
index f3bbf6df1..20383136a 100644
--- a/client/tests/gen_client_fixtures.gd
+++ b/client/tests/gen_client_fixtures.gd
@@ -12,6 +12,7 @@ extends SceneTree
 
 var _Msgpack: GDScript
 var _count := 0
+var _errors := 0
 var _output_dir: String
 
 
@@ -22,27 +23,48 @@ func _init():
 func _run():
 	_Msgpack = load("res://addons/messagepack/messagepack.gd")
 
+	# Resolve repo root from Godot project root (client/).
+	# Assumes client/ is one level below repo root — validated below.
 	var project_root := ProjectSettings.globalize_path("res://")
 	var repo_root := project_root.rstrip("/").get_base_dir()
 	_output_dir = repo_root.path_join("server/tests/fixtures/gdscript")
 
+	if not DirAccess.dir_exists_absolute(repo_root.path_join("server")):
+		push_error("Repo root detection failed: %s/server/ does not exist" % repo_root)
+		quit(1)
+		return
+
 	DirAccess.make_dir_recursive_absolute(_output_dir)
 
 	_generate_inputs()
 	_generate_boundary_inputs()
 	_generate_batch()
 
+	if _errors > 0:
+		push_error("FAILED: %d encode errors encountered" % _errors)
+		quit(1)
+		return
+	if _count == 0:
+		push_error("FAILED: no fixtures generated")
+		quit(1)
+		return
 	print("Generated %d GDScript fixtures at %s" % [_count, _output_dir])
 	quit()
 
 
 func _write_fixture(name: String, bytes: PackedByteArray) -> void:
+	if bytes.is_empty():
+		push_error("Encode produced empty bytes for fixture: %s" % name)
+		_errors += 1
+		return
 	var path := _output_dir.path_join(name + ".msgpack")
 	var file := FileAccess.open(path, FileAccess.WRITE)
 	if file == null:
 		push_error("Failed to write fixture: %s (error: %d)" % [path, FileAccess.get_open_error()])
+		_errors += 1
 		return
 	file.store_buffer(bytes)
+	file.flush()
 	file.close()
 	print("  Wrote %s (%d bytes)" % [name, bytes.size()])
 	_count += 1
@@ -90,10 +112,11 @@ func _encode_inputs(inputs: Array) -> PackedByteArray:
 
 
 func _generate_inputs() -> void:
-	# Unit variants: movement directions (tick=100)
-	_write_fixture("input_move_north",
-		_encode_input(100, "MoveNorth"))
-	for dir_name in ["MoveNortheast", "MoveSoutheast", "MoveSouthwest", "MoveNorthwest"]:
+	# Unit variants: all 8 movement directions (tick=100)
+	for dir_name in [
+		"MoveNorth", "MoveSouth", "MoveEast", "MoveWest",
+		"MoveNortheast", "MoveSoutheast", "MoveSouthwest", "MoveNorthwest",
+	]:
 		_write_fixture("input_%s" % dir_name.to_snake_case(),
 			_encode_input(100, dir_name))
 
@@ -108,8 +131,14 @@ func _generate_inputs() -> void:
 	# Other unit variants
 	_write_fixture("input_pause",
 		_encode_input(100, "Pause"))
+	_write_fixture("input_unpause",
+		_encode_input(100, "Unpause"))
 	_write_fixture("input_toggle_stance_up",
 		_encode_input(100, "ToggleStanceUp"))
+	_write_fixture("input_toggle_stance_down",
+		_encode_input(100, "ToggleStanceDown"))
+	_write_fixture("input_walk_away",
+		_encode_input(100, "WalkAway"))
 
 
 func _generate_boundary_inputs() -> void:
diff --git a/docs/DEVOPS.md b/docs/DEVOPS.md
index 56c47d6c7..162c07568 100644
--- a/docs/DEVOPS.md
+++ b/docs/DEVOPS.md
@@ -82,6 +82,12 @@ The bidirectional protocol is validated by two sets of committed fixtures:
 
 Regenerate both after any protocol change. Commit the updated fixtures alongside the code change.
 
+**Troubleshooting fixture failures:**
+
+- **`make fixtures-client` fails with encode errors:** Check that `client/addons/messagepack/messagepack.gd` is up to date. The script exits non-zero on any encode failure.
+- **`gdscript_generated_fixtures_deserialize` fails:** Fixtures in `server/tests/fixtures/gdscript/` are stale or corrupted. Re-run `make fixtures-client` and commit the updated files.
+- **Fixture staleness in `make pre-pr`:** Protocol changed but fixtures were not regenerated. Run `make fixtures && make fixtures-client`, then commit both `client/tests/fixtures/` and `server/tests/fixtures/gdscript/`.
+
 ### Lint
 
 ```bash
diff --git a/server/tests/serialization.rs b/server/tests/serialization.rs
index 3366279fe..2a094c5d4 100644
--- a/server/tests/serialization.rs
+++ b/server/tests/serialization.rs
@@ -1013,15 +1013,14 @@ fn malformed_input_in_batch_rejects_entire_batch() {
 /// (runs client/tests/gen_client_fixtures.gd via Godot headless)
 #[test]
 fn gdscript_generated_fixtures_deserialize() {
+    // CWD is server/ when cargo test runs (Cargo sets it to the package root)
     let fixture_dir = std::path::Path::new("tests/fixtures/gdscript");
 
-    if !fixture_dir.exists() {
-        eprintln!(
-            "SKIP: GDScript fixtures not found at {}. Run `make fixtures-client` to generate.",
-            fixture_dir.display()
-        );
-        return;
-    }
+    assert!(
+        fixture_dir.exists(),
+        "GDScript fixture directory not found at {}. Run `make fixtures-client` to generate.",
+        fixture_dir.display()
+    );
 
     let mut count = 0;
     for entry in fs::read_dir(&fixture_dir).expect("read gdscript fixture dir") {
@@ -1088,13 +1087,11 @@ fn gdscript_generated_fixtures_deserialize() {
         count += 1;
     }
 
-    if count == 0 {
-        eprintln!(
-            "SKIP: no .msgpack files found in {}. Run `make fixtures-client` to generate.",
-            fixture_dir.display()
-        );
-        return;
-    }
+    assert!(
+        count > 0,
+        "No .msgpack files found in {}. Run `make fixtures-client` to generate.",
+        fixture_dir.display()
+    );
     eprintln!("Verified {} GDScript-generated fixtures", count);
 }